1. Field of the Invention
The present invention relates to an apparatus and method for manufacturing an automotive seat of type comprising a preformed seat padding and a top cover member bonded to the surfaces of the foam seat padding.
2. Description of the Prior Art
Generally, among various conventional automotive seats, there has been available such a seat that is formed by bonding a top cover member to a foam sea padding or cushion member which has been formed in a mold into a predetermined seat shape together with a metallic frame, so that the top cover member is affixed over the foam padding along its uneven surface. This bonded type of seat is advantageous in that the top cover member is easily bonded to the foam seat padding or cushion member in a close contact therewith without necessity of pulling the top cover member into the seat padding by use of an anchoring member and insert wire embedded in the cushion member, which simplifies the manufacturing steps and does not cause adverse effect on the whole seat even if a partial deformation occurs in the seat during the manufacturing process, in contrast to an integrally foamed seat which is formed by foaming a foamable material together with a top cover member within a mold.
In practical, according to the above-stated bonded-type seat, a hitherto method for making the same involves placing a preformed seat padding on a lower die, applying an adhesive to the surface of the seat padding, affixing a top cover member over the seat padding, the top cover member being formed in a configuration conforming to that of the seat padding, and pressing an upper die against both top cover member and seat padding, so as to bond the top cover member to the seat padding. Those steps, however require a precision for forming the top cover member in conformity with the outer shape of the seat padding, and also require a bonding process per seat by use of a pressing means. To expedite such troublesome steps, the inventors of the present invention previously made a seat manufacturing apparatus known from the U.S. Pat. No. 4,764,241, according to which four lower dies are provided on a turntable which is rotatable intermittently at 90 degrees in a circular direction, the four lower dies being equally defined on the turntable in its circular direction, and the apparatus further comprises various mechanisms for supplying the top cover member to the lower dies, applying a heat to the cover member, forming same into an desired uneven shape, and pressure bonding the foam cushion member and cover member together, and, with this system, when the lower dies are rotated at 360 degrees, a complete unit of seats is produced for one automobile. Such automatical apparatus has an advantage over the foregoing prior art in terms of rapidity and smoothness in manufacturing the seat.
However, a disadvantageous aspect has been perceived even in the U.S. Pat. No. 4,764,241, in that those independently disposed four mechanisms are rather complicated in structure, and the circular arrangement of them takes up much of room around the apparatus, which is unsuitable for installation in a small space. Also, that prior art has been found disadvantageous in that the rotation of the turntable has to be stopped each time hat a new top covering member is affixed to the lower die, during which all the heating, forming and pressure-bonding mechanisms are provisionally forced to be in non-operation state, and consequently, it is a time-consuming factor that prevents a smooth and high-efficient flow of the seat assembling processes.